20080225-bird nest soup werid food2.jpg Bird's nest soup is a soup made from the nest of a kind of cave-dwelling swift. It is regarded as a delicacy, health booster, life prolonger and aphrodisiac in Asia, particularly in China and Hong Kong, and is said rejuvenate skin, clear up complexions, clean out the digestive track, and cure lung cancer. [Source: Eric Valli, National Geographic, January 1990; Roy Andries de Groot, Smithsonian]

The translucent, gelatinous material used to make the bird nest gives the soup richness and texture and was compared by an 18th century adventurer with the foam of wave crests. Chinese have made the nest material into a jelly mixed with spices or sweets as well as soup. The taste? One producer said, it was “sort of like a piece of paper.” The nest material has little flavor and generally is cooked with something else to be give it flavor.

Bird's nest soup was invented around 1750 by a Siam-based Chinese man named Hao Yieng who discovered the "wind-eating" swiflets and learned that their nests were soluble in water. In 1770, the King of Siam, granted Hao Yieng a monopoly on the bird nest trade. He promptly became rich. Later the Siamese took back control of the nests and a "corps of hereditary collectors" was established.

A kilogram of top quality bird's nests can go for $3,000 to $4,000, half the price of gold, and is the product of about 120 nests. A tureen of soup for four people of "Nest of Sea Swallows with Venomous Snake and Chrysanthemum Petals with Lemon grass Lotus Seeds in Soup"—with several drops of venom squeezed from the glands of a snake that pulled out a bag—can go for $100 or more in Hong Kong and is made from six nests.

Bird's Nest Swiftlets

The nests used for the soup are made by three bird species: 1) the edible-nest or white-nest swiftlet; 2) Germain’s swiftlet; and 3) the black-nest swiftlet. These birds live primarily in large limestone caves on islands or near the sea in Southeast Asia. Sometimes called "sea swallows," the small swifts feed on flying insects and navigate through caves like bats using echolocation.

Both males and females participate in nest building. The sticky gelatinous noodle-like fibers used to make the nests are secreted by well-developed salivary glands in their mouth The glands enlarge during the breeding season. When the fibers harden they produce a glue that hold the nest together and keeps it attached to the cave. The incubation period for the eggs is 19 to 23 days. Young remain in the nest for an additional six to eight weeks.

The best nest come from swiftlets that live deep inside caves. These birds echoloccate with a series of high pitched clicks and rattles that increase in frequency from five a second in open spaces to twenty a second near walls. Distance is determined by amount of time it takes the sounds to bounce off the wall and return to the ear. Direction is determined by the minute difference between the time sound reaches each ear. The system is effective but crude compared to echolocation system of bats.


leftSwifts are among the world’s fastest-flying birds. Their narrow, swept-back, scimitar-shaped wings allow them to not only flay fast, but also to make dramatic dives, acrobatic moves and dart around here and there. There are about 80 different swift species. They are found mostly in the tropics but can be also found in cold areas such as Alaska and Siberia. Many make long migration flights, some over long stretches of open ocean.

Most swifts are dark brown or sooty in color, have short legs and strong claws and stay aloft for months at a time They pursue food, mostly insects, in the air, mate there and presumably sleep there as well. Many swifts have wings that are so long they can not perch on the ground and legs that are so short they have difficultly taking off like other birds. Instead they have drop off from a branch, perch or a cliff side. Some species collect branches for their nest by biting off branch tips in mid flight.

Swifts belong to the family Apodiformes, which means “without feet.” Swifts do indeed have feet albeit small ones but they hardly use them as the hunt, eat and even sleep on the fly.

Swift Behavior

Some species gather in colonies. For these there is a lot of social activity in the form of group flights and vocalizations that vary from long buzzy screams to short sharp chirps. Some species can fly at speeds of 170 kilometers per hour, cover 900 kilometers, collecting insects the whole way. Females swifts that mate in mid air fold out their wings while the male lands on her back. The couple glide together and sometimes plummet hundred of feet towards the earth intertwined.

Many swifts collect the prey they capture into food ball called bolus, and bring them back to their nests. Most of the time these balls contain swarming insects such termites, mayflies, aphids as winged ants, wasps and/or bees. Sometimes several hundred individuals from 60 different species can be found in a single bolus.

Some species of swift are able endure short periods of cool weather by entering a semitropic state with a lowered body temperature. Some swiftlets roost deep in caves in total darkness. These birds used echolocation like bats to navigate around. Non-echolocation swiftlets near the entrance of caves where there is enough light to see.

Swift Speed

Swifts sleeping or “roosting” in flight have been studied with radar. Observations show that they maintain an average speed of 20 mph, periodically flapping to maintain their speed and height. Studies of swift wings in wind tunnels shows that a speed of 20 mph gives the birds the maximum gliding time for the least amount of energy.

Swifts have been clocked going speeds of 60 mph. At high speeds they cock back their wings in a swept-back position. Wind tunnel studies indicate this position is more energy efficient at speeds over 40 mph as drag is reduced and enough lift is provided. When turning, spread wings are good at speed of 20 mph or lower but at speeds above 30 mph stiffened wings held closer the body keep the wings from being damaged by high forces and turbulent air.

These days, scientists are studying swifts for insights into aircraft wing development in part because they don’t flap their wings much when they glide or dive. Swift wings resemble long, thin, curved blades that taper off at the end sort of like a scythe. They gain added maneuverability by having an unusually larger proportion of their wings made up of the “hand” or wing tip bones. By changing the “wrist” angle between the “hand” and forelimb, the swift can change both the shape of the wing and its area, thereby maximizing their efficiency at various speeds.

Swiftlet Nests

The nests are about the size and hardness of teacups; are essentially made from hardened saliva mixed with feathers, grass and twigs; and look like congealed strands of vermicelli. The noodle-like fibers are used to bond nesting materials together and attach the nest to a vertical walls of caves or cliffs or hollow tree nesting sites.

There are two kinds of nests: white nests made up mostly of saliva and black nests with plant materials and feathers mixed in. White nests are the most valuable. They are generally made by swiftlets that nest deep inside the caves and are ideally collected before a female lays her eggs. Generally the whiter and purer a nest is the more tasty and valuable it is. Black nests are also collected. These nests can not be eaten until they have been properly cleaned.

The edible-nest swiftlet often build their nest in the most inaccessible of places: on the roofs and upper walls of high caves and even overhangs. Other species build nests the in buildings and bridges and chimneys but not the edible-nest swiftlet. Sometimes the eggs and young of edible-nest swiftlets are placed in the nest of an other species, the uniform swiftlet, which lives in buildings. There are some claims that a third of nest form Indonesia are taken from swiftlets that have made their nests in buildings.

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boxed bird's nests

Making Swiftlet Nests

To make a nest a swiftlet moves its head back and forth like a weaving bobbin. David Attenborough wrote: “The bird starts by flying persistently in front of its chosen site and repeatedly dabbing the rock with its tongue, laying down a curved line of saliva which marks the lower edge of the nest-to-be. The saliva dries and hardens quickly and with repeated flights, the bird slowly builds up the low line into a low wall. As soon as this is big enough to cling to, the speed of construction accelerates and within a few days the wall has become a semicircular cup of creamy white interlacing string that is just big enough to hold the customary clutch of two eggs.”

The swiftlet are so small they don't have the strength to pick up nesting materials such as twigs and leaves from the ground like other birds. Instead they pick up pieces of feather, fragments of dried grass and other small things they find floating in the air and affix the to a surface their "sticky spittle.” Nests near the entrance to the caves have large amounts of feathers. Those that are deeper inside are made primarily of spittle, and are thus more desirable. .

The swifts can take up two months to build a nest. Ideally the nest is collected after fledglings have take wing rather than before eggs of hatched. That way there are more birds o create nests. After the nests are harvested they are soaked in water ti soften them up and a magnifying glass is used to pick out loose impurities like twigs and feathers. After being steamed or boiled the nest separate into long chewy strands. About half the material in protein. What health benefits might be found in the nests are believed to be lost during the cleaning process.

Bird's Nest Collectors

Nests are collected at Niah caves in Sarawak, Gomantong Cave in Sabah and the Phnag Nga Bay area in Thailand. At Gomantong Cave the nests are collected twice a year: once before the eggs are laid and again after the male has made a second nest and the fledglings are gone.

The nests are harvested by men that sometimes climb hundreds of feet up to roofs of flimsy bamboo and rattan ropes and scaffolding. The men use special knives and three-pronged tweezers—blessed by the cave spirits—to cut and pull the nests off the cave walls. To get to some caves they have to swim through underwater tunnels, shimmy down vines from cliff tops.

Collectors spend ay ear or more learning how to climbs the bamboo scaffolding. They often stay in the caves all day, in some cases feeding themselves on swiftlets eggs they collect. They are often watched while they work and sometimes searched to make sure they haven’t hidden any nests. The work is very dangerous. Some men climb among the bamboo at dizzying heights for decades with no mishaps. Others aren't so lucky, every year several nest gathers die or become seriously injured. The bamboo ropes deteriorate within a couple years. . How do you tell a good bamboo rope from a bad one. If it sounds hollow like cardboard it is no good. Bird's nest gatherers who work on the rugged cliffs on the southern side of Java have to deal with strong tides and large waves blown up from Antarctica. The Blair brothers talked to one gatherer who misjudged the tides and got stuck inside a cave for 32 days. In the darkness he survived by eating bird's nest and grubs that eat the bird and bat dung on thee floor of the cave. [Source: "Ring of Fire" by Lawrence and Lorne Blair, Bantam Books, New York]

Bird's Nest Soup Business

Bird's nests are a multibillion dollar business in Asia. Between 1992 and 1998, 985 tons of swiflet nests, valued at $700 million, was imported by Hong Kong. A large protion of it was transhipped to China. Much more is believed to have made its way to Hong Kong along undergrond channels. Indonesia is the biggest supplier of nests followed by Thailand, Vietnam, Singapore, Myanmar, Malaysia, India and Sri Lanka.

Demand for bird nests increased 30 fold between the 1960s and the 1980s as Asian became more affluent. The increase in demand has meant higher prices. Prices are so high there is even a market for fake nests made from gum extracts.

Harvesting is controlled and regulated to protect the birds and make the sure the supply of bird’s nests is not depleted. Companies pay government as much as $500,000 a year for the right to collect bird nests in certain caves or certain islands. There is believed to be to large payoffs made to obtain the rights but once they obtain the rights the companies are very secretive about what the do. The Thai government alone collects about $25 million a years from five companies that collects nests from 140 islands.

Chinese companies get their bird's nests mainly from Southeast Asia countries for processing and subsequent packaging for the local market. Malaysian bird's nest exports to China had surged from 1.44 tonnes in 2009 to 100 tonnes in 2010.

Despite nationwide crackdowns, smuggled bird's nest still end up on consumers' plates. Illegal exporters revealed that they smuggled the food into China along with shipments of other goods through ports in Guangdong and Fujian provinces and Shanghai. Their agents retrieve the goods at the ports and courier them to buyers to evade inspections by watchdogs. "There will be no certificate of health for these bird's nest. Not having to obtain certification from both the Malaysian and Chinese authorities has saved us a lot of money and work," said a Malaysian bird's nest producer. [Source: Chow How Ban in Petaling Jaya, The Star, Asia News Network, August 27 2011]

Bird's Nest Buildings

In the southern Thai town of Pattani some building owners have found that it is more profitable to allow bird’s nest swiftlets to occupy their buildings than to rent the spaces to humans. One hotel owner told the New York Times, “With people, you need to have someone to manage the buildings. But with birds, there’s no management, no maintenance, you just wait.”

Thousands of birds occupy the properties. In some cases people have left their own homes to let them be occupied by birds. In other cases buildings have security cameras to deter poachers and windows that automatically shut at night to keep away predators. In yet other cases people have built special four-story boxes that have small holes instead of windows. Only a few of these have attracted birds.

Some buildings are made to imitate caves that birds natural live in. Careful studies that take into consideration wind patterns and bird migration routes are made to figure out where to place the buildings. Sometimes recorded swiflet sings are played to attract newcomers. Some even have recorded sounds of waterfalls to attract birds.

A typical building set up for bird’s nest swiftets has a two foot square opening used by the birds to enter the building. The building is kept dark like a cave and smells of bird droppings. Many have steel doors and heavy locks to thwart possible bird nest thieves. The nests are collected about once every three months. Some people who live near the bird houses complain of the smell of the dropping and noise of recordings used to attract birds.

Harvesting bird’s nests from inside buildings can be particularly lucrative because the nests are easy and cheap to gather and they can be gathered after the eggs have hatched and the fledglings have taken wing so there are more birds that can make nests in the future, . The brod are encouraged to nest on wood because the nest can be removed more cleanly and easily than they can on cement or plaster walls.

Bird's Nest Soup Violence

Because the birds nests are so valuable poaching is a problem. Some caves are protected by guards, armed with assault rifles, barbed wire and booby traps. The guards have orders to shoot interlopers on sights. Between 1992 and 1994, guards for one company shot and killed 29 people who they claimed were stealing nests. Some were shot at close range, execution style. On several occasions fishermen who were at the wrong place at the wrong time were shot.

In Thailand, the bird’s nest business is particularly nasty. A number of unsolved murders and extortion cases are believed to be connected with it. In one case an owners of tourist kayaking company that sponsored trips among islands with bird nest in the Krabi area received death threats because they refused to pay protection money to a bird nest company that claimed the kayakers disturbed the birds.

After one owner was shot as seriously injured and some tourists were threatened at gunpoint and the government did little to help them the kayaking company decided to pay the $2.75 per-head protection money for each tourist. The birds nest collectors were believed to be in cahoots with local politicians.

Endangered Bird’s Nest Swiftlets

The business is so lucrative and so many nests are collected before the swiftlets have a chance to lay their eggs, there are worries the swiftlets may become endangered. In some cases, birds have their nests snatched two or three times before they get a chance to lay eggs. In other cases poachers take the nests and toss the eggs or young birds to the ground. By one estimate, half a million eggs have been lost in one cave system in Sabah alone.

Poaching is difficult to control because the of the remote location of some of the caves. The laws on the books that regulate harvesting, poaching, selling, importing and exporting nests the laws are difficult to enforce.

Studies have indicated that populations of some swiftlet communities have declined as a result of poaching Some caves have only a third of the nests they once had. Some have abandoned completely because there are so few best it is unprofitable to collect them. By one estimate the overharvesting of nests and destruction of swiftlet habitats led to a decline in the number of birds by 73 percent in some areas between 1962 and 1990.

Fake Bird Nests

Fake bird’s nests are a problem, The fake bird’s nests were sold at RMB 15-30 per gram, while genuine bird’s nests are usually sold at RMB 38 per gram at least, with some of them even sold at RMB 78 per gram. At present, there are nearly 200 bird’s nest stores in Xiamen. Apart from some franchise stores owned by famous brands which are protected by brand laws, most of the stores are selling different bird’s nest products. [Source:]

Therefore, most counterfeiters choose new brands to manufacture fake bird’s nest products.“Those news brands which just gain popularity in the market have a certain market share so that fake bird’s nest can also sell well, “according to Mr Wu, the principal of one bird’s nest specialty shop in Xiamen.

An industry insider said that due to the lack of supervision and standards in the bird’s nest market, fake products appear frequently. Unlike other food, bird’s nest is free from routine sampling of by the Quality Supervision Department. And bird’s nest does not belong to health care products so that it is not subject to drug authorities. The insider added that while customers are purchasing bird’s nest products, it is necessary to ask for relevant certificates, such as a sales certificate, hygiene certificate and certificate of imported good

Method of distinguish real and fake bird’s nest: Some kinds of fake bird’s nest are designed as if they are real. Customers who have little experiences of distinguish are easily to be cheated. To avoid this they need to observe the real bird’s nest at the dealers of brand companies. Otherwise color and smell are good indicators of fake bird’s nests. The real nest is orange, red. The fake one is white, made of agar or agenate mix with flour. The real nest has a fishy, mouldy smell. The fake one has hardly any of this smell. It has strange pungent smell. Customers who buy bird’s net can test by dipping it in the water. If the nest is faked, it will become pasty. The real nest will not be pasty. The other method is to put the nest in iodine solution. If it was faked, it will turn into blue. For blood bird’s nest, it will become red or pink when dipped into tea water. If it was faked it will become darken. If the nest is dyed, the coloring will dissolve into water. The real nest remains it color when boiling in water. In summary, if customers need to by bird’s nest, they should get consultancy from experts because they can specify whether the nest is real or faked.

Tainted Bird Nests

Chow How Ban wrote in The Star, a Malaysian newspaper, “China has ordered a national check on red bird's nest after samples were found to have higher than permitted nitrite levels. But the shocker was that blame was put on Malaysian exporters. A spot check conducted on red cubilose, better known as red bird's nest, in East China's Zhejiang province has developed from an isolated case into a national affair, and threatens to go international. [Source: Chow How Ban in Petaling Jaya, The Star, Asia News Network, August 27 2011]

Local market watchdogs have been ordered by China's federal government to carry out inspection on all edible bird's nest in the market in view of serious industrial contamination. Results from recent tests conducted by the Zhejiang Administration for Industry and Commerce on more than 30,000 cups of red bird's nest in the past two months showed that almost all the samples contained nitrite levels in contravention of China's health standards, with some up to 350 times above levels. Nitrite is a toxic substance that may lead to chronic poisoning.

The authorities blamed it on cubilose imports from Malaysia. Malaysian bird nest exporters, stunned by the allegation, said Malaysia had never been known as a producer of the so-called "blood-red cubilose". They suspect some bad apples in the industry could have made the fake bird's nest for a quick kill.

Checks at a wholesale market and several other retail outlets in Beijing revealed that all bird's nest products had been removed from the shelves; and retailers were awaiting the authorities' green light for the sale of the nutritious food again "It is a risk to sell or even display bird's nest now as the authorities will come and check our products regularly," said Xu Shuhan, a wholesaler from Hongyuan Abalone & Shark's Fin Trading Company at the Da Hong Men Wholesale Market. "Not only that, they will take away boxes of samples for examination, and it will be a big loss for us. So, it is better to stop selling them."

He said he had turned away many dealers and customers seeking to buy bird's nest under the counter. A sales promoter from the Long Xi Shang Pin wholesale outlet said they had been keeping their bird's nest products in the storeroom for about two weeks now to avoid any problem with the authorities.She said they sourced their products from Guangdong province, but could not tell which country they were imported from.

Li Yumei, a chain store owner of Yanzhiwu, one of China's largest bird's nest chains, said she had removed all the cubilose products, both white and red bird's nest, from her store in the Shuangjing area and sent them for inspection. In August 2011 Xiamen Suntama Industry Development Co Ltd, the owner of Yanzhiwu brand, said the company had ordered all its chain stores around China to stop selling their product, a day after the State Administration for Industry and Commerce notified all local departments to beef up inspection and enforcement on bird's nest to ensure food safety.

While consumers no longer can buy bird's nest from retailers, it is still available online or directly from dealers. "The red cubilose episode will help boost sales of the white bird's nest which I am selling," said Y.M. Sim who sells cubilose online. Fuciphagus Agritech Sdn Bhd CEO Moh Chee Hong said it was business as usual for his company which has legal documentation to export bird's nest to China. But his business had slowed 20 percent due to product recall faced by his buyers.

"We encountered a case two weeks ago when 5kg of our bird's nest were denied entry at Xiamen because the Chinese Customs said they had updated their requirements for the nitrite level in bird's nest, despite our products having already met the Malaysian standard for export," he said. "After discussions, they accepted our explanation and allowed our goods through." Officials from the Malaysian Department of Veterinary Services (DVS) and several Malaysian exporters flew into Beijing on Friday to address the Chinese press on Malaysian bird's nest.

Image Sources:

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, Chinese government, Compton’s Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

Last updated July 2015

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